Mountable holder for a bag containing a fluent substance



FIG. 1 is a perspective view of a mountable holder for a bag containing a fluent substance showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a side elevational view thereof; and

FIG. 4 is a top plan view thereof. 

The ornamental design for mountable holder for a bag containing a fluent substance, substantially as shown. 